Abstract

A Gram-staining-positive, aerobic organism, isolated from the Red Sea sponge Spheciospongia vagabunda was investigated to determine its taxonomic position. On the basis of results of 16S rRNA gene sequence analysis strain EG49(T) was most closely related to Actinokineospora cibodasensis and Actinokineospora baliensis (both 97.3 % similarity) and Actinokineospora diospyrosa and Actinokineospora auranticolor (both 97.0 % similarity). The 16S rRNA gene sequence similarity to all other species of the genus Actinokineospora was <97.0 %. The quinone system of strain EG49(T) contained the menaquinones MK-9(H4) (47 %), MK-9(H6) (27 %) and MK-9(H2) (15 %) in major amounts. Minor amounts of MK-7(H4) (2 %), MK-9(H0) (1 %), MK-9(H8) (3 %) and MK-10(H4) (3 %) were detected as well in addition to MK-8(H4), MK-8(H6), MK-10(H2) and MK-10(H6) (all <1 %). The diagnostic diamino acid of the peptidoglycan was meso-diaminopimelic acid. In the polar lipid profile, diphosphatidylglycerol, phosphatidylethanolamine and hydroxyphosphatidylethanolamine were predominant. Phosphatidylinositol-mannoside, two unidentified phospholipids and two glycoglipids as well as one aminoglycolipid, one aminolipid and one unidentified lipid were found in addition. The fatty acid profile was composed of mainly iso-branched fatty acids: iso-C16 : 0, iso-C14 : 0, iso-C15 : 0 and iso-C16 : 1H. All these findings clearly supported the classification of the strain as representing a member of the genus Actinokineospora. In addition, the results of physiological and biochemical tests also allowed phenotypic differentiation of strain EG49(T) from the most closely related species of the genus Actinokineospora. Strain EG49(T) represents a novel species of the genus Actinokineospora, for which we propose the name Actinokineospora spheciospongiae sp. nov., with strain EG49(T) ( = DSM 45935(T) = CCM 8480(T) = LMG 27700(T)) as the type strain.